Add pow metrics

src/pow/pow.service.ts

@@ -1,5 +1,6 @@
 import { CACHE_MANAGER } from '@nestjs/cache-manager';
 import { Inject, Injectable, Logger } from '@nestjs/common';
+import { InjectMetric } from '@willsoto/nestjs-prometheus';
 import { Cache } from 'cache-manager';
 import { randomBytes, createHash } from 'crypto';
 
@@ -11,7 +12,14 @@ export class PowService {
 
     constructor(
         @Inject(CACHE_MANAGER) private cacheManager: Cache,
-    ) { }
+        @InjectMetric('challenges_generated') private challengesGenerated: any,
+        @InjectMetric('challenges_completed') private challengesCompleted: any,
+        @InjectMetric('successful_verifies') private successfulVerifies: any,
+        @InjectMetric('failed_verifies') private failedVerifies: any,
+        @InjectMetric('difficulty') private powDifficulty: any,
+    ) {
+        this.powDifficulty.set(this.difficulty);
+    }
 
     /**
      * Generate a proof of work challenge, stored to redis for verification within
@@ -19,7 +27,8 @@ export class PowService {
      */
     async generateChallenge() {
         const challenge = this.generateRandom256BitString();
-        console.log(challenge)
+        this.logger.verbose(`Generated challenge: ${challenge}`);
+        this.challengesGenerated.inc();
         await this.cacheManager.set(challenge, true, 60 * 1000);
         return challenge;
     }
@@ -44,10 +53,17 @@ export class PowService {
      */
     async verifyChallenge(challenge: string, proof: string): Promise<boolean> {
         const expected = await this.cacheManager.get<boolean>(challenge);
-        return expected ? this.hashAndCheck(proof + challenge) : false;
+        const success = expected ? this.hashAndCheck(proof + challenge) : false;
+        if (success) {
+            this.successfulVerifies.inc();
+        } else {
+            this.failedVerifies.inc();
+        }
+        return success;
     }
 
     async markChallengeAsComplete(challenge: string) {
+        this.challengesCompleted.inc();
         await this.cacheManager.del(challenge);
     }
 
@@ -76,6 +92,7 @@ export class PowService {
      */
     setDifficulty(difficulty: number) {
         this.difficulty = difficulty;
+        this.powDifficulty.set(this.difficulty);
     }
 
     /**